Safety: Electric Current in the Human Body

The following information is from the U.S. Occupational Safety and Health Administration's (OSHA) publication 3075, Controlling Electrical Hazards, available at https://www.osha.gov/Publications/3075.html or https://www.osha.gov/Publications/osha3075.pdf.

What effect do shocks have on the body?

An electric shock can result in anything from a slight tingling sensation to immediate cardiac arrest. The severity depends on the following:

• the amount of current flowing through the body,

• the current's path through the body,

• the length of time the body remains in the circuit, and

• the current's frequency.

This table shows the general relationship between the amount of current received and the reaction when current flows from the hand to the foot for just 1 second.

Effects of Electric Current in the Human Body

Current Reaction

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Below 1 milliampere Generally not perceptible

1 milliampere Faint tingle

5 milliamperes Slight shock felt; not painful but disturbing. Average individual can let go. Strong involuntary reactions can lead to other injuries.

6–25 milliamperes (women) Painful shock, loss of muscular control*

9–30 milliamperes (men) The freezing current or " let-go" range.*

50–150 milliamperes Extreme pain, respiratory arrest, severe muscular contractions. Death is possible.

1,000–4,300 milliamperes Rhythmic pumping action of the heart ceases. Muscular contraction and nerve damage occur; death likely.

10,000 milliamperes Cardiac arrest, severe burns; death probable

* If the extensor muscles are excited by the shock, the person may be thrown away from the power source.

Source: W.B. Kouwenhoven, " Human Safety and Electric Shock," Electrical Safety Practices, Monograph, 112, Instrument Society of America, p. 93. November 1968.